Friday's school shootings in Connecticut are something that parents must discuss with their children.

How to talk about it, and what to say, will depend on the age of child, experts say. For children of any age, the most important thing a parent can do is to assure them that they are safe, then find out what they know about the tragedy by asking an open-ended question.

"The first, most important thing: Give your kids a big hug. With this horrific tragedy there are so many emotions," Gurwitch said. "With so many adults feeling it, so are children. Schools are supposed to be the safe place. This shatters that idea."

Gurwitch, a faculty member at Duke University Medical Center in North Carolina, said parents need to avoid thinking they should "protect" their kids by not talking about the tragedy.

"It's important to start the conversation. If you have a child who is involved with social media in any way, shape or form, they know about it," she said. Even the youngest kids could have heard something on the school bus.

She said the conversation has to be open-ended and age appropriate. It can begin with "What have you heard about what happened today in Connecticut at the elementary school?"

"Figure out what your child knows. Start the conversation. Gently correct any misinformation the child may have," Gurwitch said. "Reinforce a sense of safety and security."

As a guideline for what is appropriate, parents can approach the issue in the same way they would speak to a child about sex. Don't explain all the details to a young child, but don't pretend the tragedy didn't happen — children will find out about it, said Marguerite Vanden Wyngaard, Albany school district superintendent. She said older children will want to know why it happened.

"You have to explain it simply, you have to explain it in terms they would understand," she said. "You're listening for signs of worry, you're listening for signs of fear." She recommended that parents reassure children that they are safe by locking the doors in front of them and by giving them extra hugs.

It's essential to answer all of your child's questions, said Jane Katch, author of "Under Deadman's Skin: Discovering the Meaning of Children's Violent Play." She said it is equally important to filter some answers so that the worst details are not revealed. She said parents shouldn't be surprised if children incorporate the tragedy into their play and that it is a normal and healthy way for them to process things. Rather than discouraging such behavior, it can be used as a way to further the conversation, she said.